/*!	 layer_switch.h
**	 Header file for implementation of the "Switch" layer
**
**	......... ... 2014 Ivan Mahonin
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifndef __SYNFIG_LAYER_SWITCH_H
#define __SYNFIG_LAYER_SWITCH_H

#include "layer_pastecanvas.h"

namespace synfig
{
/*!	\class Layer_Switch
**	 Class of the Switch layer.
*/
class Layer_Switch : public Layer_PasteCanvas
{
    // Layer module: defines the needed members to belong to a layer's factory.
    SYNFIG_LAYER_MODULE_EXT
private:
    // Parameter: (String) Active Layer Name
    ValueBase param_layer_name;

    mutable std::set<String> last_possible_layers;
    mutable std::set<String> last_existant_layers;

    sigc::signal<void> signal_possible_layers_changed_;
    void possible_layers_changed();

public:
    // Default constructor
    Layer_Switch();
    // Destructor
    virtual ~Layer_Switch();
    // Returns a string with the localized name of this layer
    virtual String get_local_name()const;

    //	Sets the parameter described by \a param to \a value. \see Layer::set_param
    virtual bool set_param(const String & param, const synfig::ValueBase &value);
    // Get the value of the specified parameter. \see Layer::get_param
    virtual ValueBase get_param(const String & param)const;
    // Gets the parameter vocabulary
    virtual Vocab get_param_vocab()const;

    Layer::Handle get_current_layer()const;

    sigc::signal<void>& signal_possible_layers_changed()
    {
        return signal_possible_layers_changed_;
    }

    virtual void on_childs_changed();
    virtual void on_static_param_changed(const String &param);
    virtual void on_dynamic_param_changed(const String &param);
    virtual void on_possible_layers_changed() { }

    void get_existant_layers(std::set<String> &x) const;
    void get_possible_layers(std::set<String> &x) const;
    void get_possible_new_layers(std::set<String> &x) const;
    void get_impossible_existant_layers(std::set<String> &x) const;

    // Sets z_range* fields of specified ContextParams \a cp
    virtual void apply_z_range_to_params(ContextParams &cp)const;
}; // END of class Layer_Switch

}; // END of namespace synfig

#endif